In recent years, many techniques for distributing privacy information safely are proposed. For example, as the techniques of this kind, the techniques described in Patent Literatures 1 to 3 are exemplified.
In Patent Literature 1, a data disclosure apparatus is proposed which can provide privacy data of a person while preventing the person from being inferred, in a method of providing privacy data. This data disclosure apparatus is provided with a retaining section of retaining one or more of data, each of which has one or more attributes. An anonymity calculating section calculates anonymity when a specific attribute of the data is disclosed. A grading change disclosure section changes the grading of data of the specific attribute, when the calculated anonymity does not have desired anonymity, and disclosures the data of the attribute which meets anonymity above a desired threshold. Such a data disclosure apparatus can discloses individual data which cannot be disclosed because the anonymity securing is difficult, by making a description grading rough.
An information mediating system is disclosed in Patent Literature 2 which discloses privacy data outside safely. The information mediating system has a user terminal, an information provider terminal and a mediating server. The mediating server is provided with a section of collecting and storing provision data from the information provider terminal, a section of accumulating attribute data of the information provider, and a section of retaining a disclosure condition of a combination of each item of the provision data and each item of attribute data. The mediating server can disclose the combination according to the disclosure condition, and provides data by rewriting data for collecting the provision data and the attribute data for every name with dummy data, when the disclosure of the combination is not permitted. Such an information mediating system can change a method of data disclosure by defining a disclosure range of the provision data to a user in detail.
In Patent Literature 3, a member data management center apparatus is disclosed, in which an adequate service is provided to each of members while protecting the privacy of the member. This member data management center apparatus is provided with a plurality of individual member information databases for managing individual member data related to an individual member IDs, and a secondary member data database for managing secondary member data related to a secondary member ID. The member data management center apparatus receives correspondence relation between the individual member ID and the secondary member ID from a member service providing apparatus, in which the individual member ID and the secondary member ID are related, groups the member data for every name, and generates abstracted individual member data by carrying out processing to prevent the member from being inferred uniquely. Moreover, the member data management center apparatus generates and stores name-based grouping member data which contains the secondary member ID and the abstracted individual member data in the secondary member data database, and discards the correspondence relation between the secondary member ID and the individual member ID. In such a member data management center apparatus, the grasping of detailed member data every member is difficult even if the member data is exposed just as it is, and the privacy of the member can be kept in a constant level.